The section headings used herein are for organizational purposes only and are not to be construed as limiting the subject matter described in any way.
A transmission or gearbox generally provides speed and torque conversions from a rotating power source, such as, for example, a motor, to another device using gear ratios. In large electric systems, such as, for example, electric vehicle drive trains, a transmission adapts the output of an electric motor to a vehicle's drive wheels. The transmission reduces a high motor speed to a slower wheel speed, increasing torque in the process. Transmissions generally have multiple gear ratios (or simply “gears”), with the ability to switch between gears ratios as the vehicle's speed varies.
Due to size and weight constraints, transmissions are typically not used in small electric systems (i.e., with small electric motors), such as, for example, robotic joints and small mobile robots. Because small motors are generally not capable of switching between gears, such devices are presently limited to a single torque output, generally being considered either strong and slow (i.e., with high torque and low speed), or weak and fast (i.e., with low torque and high speed).
It may, therefore, be desirable to provide a transmission assembly that is scalable to any size input motor, allowing for an increased dynamic output range (i.e., torque and speed range) in small electric systems, such as, for example, robotic joints. It also may be desirable to provide a transmission assembly that is able to reliably shift between drive-modes, in a fraction of an actuator time-constant, to optimize motor strength, speed, and efficiency. Furthermore, it may be desirable to provide a transmission assembly that provides failsafe operation, preventing transmission failure while passing through a neutral state.